What is the ruling on delaying Zakat al-Fitr until after Eid day?
It is forbidden to delay Zakat al-Fitr beyond the sunset of Eid day. If someone delays it past Eid day without a valid excuse, they have committed a sin and must immediately make up for it because their obligation remains unfulfilled, and they must clear their responsibility.
Does the Obligatory Ritual Bath (Ghusl) Suffice in Place of Ablution (Wuḍūʾ)?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
The more prudent course is to perform ablution (wuḍūʾ) after the ritual bath (ghusl), so as to exit the difference of scholarly opinion and because the sufficiency of the ritual bath in place of ablution is contingent upon a number of conditions and requirements being met. And Allah the Almighty knows best.
What is the ruling on a person in a state of major impurity (junub) or a menstruating woman (ha'id) reciting the Quran from memory?
It is not permissible for a menstruating woman, a postpartum woman, or a person in a state of major impurity to recite anything from the Quran, whether from memory, from the Quran, from a phone, or a computer. It is also not permissible for them to touch the Quran, based on what was reported from Ali bin Abi Talib that the Prophet (peace be upon him) was not prevented from anything regarding the Quran except major impurity (janabah). (Reported by al-Tirmidhi who said it is a hasan sahih hadith). Menstruation and postpartum bleeding are analogous to major impurity (janabah) as they are all major impurities (hadath akbar).
For those mentioned, it is permissible to mention Allah and supplicate even with verses from the Quran, provided they do not intend them as recitation of the Quran, but intend them as remembrance (dhikr) or supplication (du'a). And Allah the Almighty knows best.
Is it permissible for a woman to wear underwear while performing Umrah?
Yes, it is permissible for a woman to wear underwear while performing Umrah. This is because she should keep her regular clothes that cover all her body while being in a state of Ihram (ritual consecration) for Hajj, or Umrah. However, she should uncover her face and hands, but it is permissible for her to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.